Improvement in valves for steam-engines



UNITED vSTATES JOSEPH W. HOPKINS, OF BROOKLYN, NEW YORK, ASSIGNOR TO HIMSELF PATENT OFFICE.

AND JAMES CLAYTON, OF SAME PLACE.

IMPROVEMENT IN VALVES FOR STEAM-ENGINES.

Specication forming part of Letters Patent N0 40,1145, dated October` 27, 1863.

To all whom it may concern:

Be it known that I, JOSEPH W. HOPKINS, of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Steam-Valve; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had tothe accompanying drawings, forming apart of this specitication, in which-` Figure l represents a plan or top view of my invention. Fig. 2 is a longitudinal vertical section ofthe same, the linear x, Fig. l, indicating the plan of section.

Similar letters of reference indicate corresponding parts in both iigures.

rIhis invention relates to auimprovement in that class of steam-valves in which the motion of the valve is partially effected by the action ofthe steam, so that the ports are wide open when the piston has arrived at either end of the cylinder, and the full force of the steam acts on the piston throughout its whole stroke. Y

My improvement will be readily understood from the drawings and the following explanation.

B represents an oscillating hollow disk, the lower part of which, at A, is made into the form of a convex slide-valve, which moves in a corresponding concave seat within the stean1- chest O, as shown in Fig. 2. The disk B is bored out to tit to the round body of the valve D,which is rigidly attached to the spindle Ef, and to which an oscillating motion is imparted by cams or other suitable means from the piston-rod.

The valve D is provided with an abutment or wing, a, which ts into a segmental cavity, b, in the disk B, and said cavity communicates with the interior of the steam-chest through the port c. The valve D, on being oscillated in the cavity of the disk B, alternately opens and closes the exhaust-channels d d', which extend on either side of the abutment a from the center of the disk to the cavity in the slide-valve A, as clearly shown in Fig. 2 of the drawings.

rIhe motion of the slide-valve is limited by stops e e on either end of its seat. If the slidevalve is not rigidly connected with the disk, the steam from the cavity b may be made to exhaust through channels passing out parallel to the spindle E through the sides of the steamchest.

The valve-chest communicates with the interior of the steam-cylinder through ports F FQ and the steam from the cylinder exhausts throughthe port E.

The operation is as follows: In the position shown in Fig. 2 the cylinder takes steam through the port F, and the piston moves in the direction of arrow l. ment, and before the piston has completed its stroke, the valve D is turned in the direction of arrow 2, against the steam which lls the cavity b, having free access to the same through the port c. As soon as the abutment b passes the port c, the channell d is opened, allowing the steam before the abutment to escape, and the space behind the abutment fills with steam and causes the disk to rotate suddenly in thedirection of arrow 3.

The port F is thereby thrown wide open and the port F broughtin communication with the exhaustport E, thus giving a full head of steam to the piston at the beginning of its re-v At the proper mol 

